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JP-7855052-B2 - Anti-reflective coating for metasurfaces

JP7855052B2JP 7855052 B2JP7855052 B2JP 7855052B2JP-7855052-B2

Inventors

  • ディアンミン リン
  • マイケル アンソニー クルグ
  • ピエール サン ティレール
  • マウロ メッリ
  • クリストフ ぺロス
  • エフゲニー ポリアコフ

Assignees

  • マジック リープ， インコーポレイテッド

Dates

Publication Date
20260507
Application Date
20241206
Priority Date
20170127

Claims (11)

  1. A method for forming an anti-reflective coating on the metasurface of an optical element, wherein the method is: To provide an optically transparent substrate having the metasurface, wherein the metasurface comprises a plurality of nanostructures forming repeating unit cells, and when viewed from above, each unit cell is A plurality of first nanostructures having a first length and a first width, wherein the first nanostructures are separated from each other by gaps along the first length of the first nanostructures, the first length is elongated in a first direction, the first widths differ from each other, and the first length is the same for a plurality of first nanostructures, A plurality of second nanostructures arranged at the ends of the plurality of first nanostructures, wherein the second nanostructures are separated from each other by gaps along a second length of the second nanostructures, each of the second nanostructures has a second length and a second width, the second length is elongated in the second direction, the second widths are different from each other, and the second length is the same, comprising a plurality of second nanostructures The second direction intersects the first direction, This includes depositing layers of optically transparent material over the plurality of nanostructures, The optically transparent layer forms the anti-reflective coating. The anti-reflective coating has a thickness configured to provide destructive interference between the image light reflected from the upper surface of the anti-reflective coating and the image light reflected from the bottom surface of the anti-reflective coating. A method wherein the layer of optically transparent material is conformally arranged across the metasurface and follows the contour of the nanostructure, without completely filling the volume separating each of the nanostructures, such that the upper surface of the optical element is non-planar.
  2. The method according to claim 1, wherein the optically transparent material comprises a polymer.
  3. The method according to claim 1, wherein the optically transparent material includes a photoresist.
  4. The method according to claim 1, wherein the distance from the uppermost surface of the nanostructure to the uppermost surface of the formed anti-reflective coating is 10 nm to 1 micron.
  5. The method according to claim 1, wherein depositing the optically transparent material layer includes spin-coating the optically transparent material across the nanostructure.
  6. The method according to claim 1, wherein the deposition of the optically transparent material layer comprises carrying out a chemical vapor deposition (CVD) process.
  7. The method according to any one of claims 1 to 6, wherein the optically transparent material layer has a refractive index, the refractive index being greater than 1 and less than the refractive index of the material constituting the metasurface.
  8. The method according to any one of claims 1 to 6, wherein the metasurface comprises a diffraction grating.
  9. The method according to any one of claims 1 to 6, wherein the metasurface comprises an asymmetric diffraction grating.
  10. The method according to any one of claims 1 to 6, wherein the metasurface comprises a Pancharatnam Berry phase optical element (PBOE).
  11. The method according to any one of claims 1 to 6, wherein the meta-surface comprises a multi-stage nanostructure.

Description

This application claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/451,587 (filed January 27, 2017), the full disclosure of said U.S. Provisional Application is incorporated herein by reference. This application incorporates by reference, in whole, each of the following patent applications: U.S. Application No. 14/555,585 (filed November 27, 2014), U.S. Application No. 14/690,401 (filed April 18, 2015); U.S. Application No. 14/212,961 (filed March 14, 2014); U.S. Application No. 14/331,218 (filed February 2015). July 14, 2014); U.S. Patent Application No. 15/342,033 (Filing Date: November 2, 2016) (Agent Reference Number MLEAP.027A); U.S. Provisional Application No. 62/333,067 (Filing Date: May 6, 2016) (Agent Reference Number MLEAP.066PR); U.S. Provisional Application No. 62/451,608, Title of Invention "DIFFRACTION" "GRATINGS FORMED BY METASURFACES HAVING DIFFERENTLY ORIENTED NANOBEAMS" (Filing date: January 27, 2017) (Agent reference number MLEAP.092PR); and U.S. Provisional Application No. 62/451,615, Title of Invention "DIFFRACTION GRATINGS BASED ON METASURFACES HAVING ASYMMETRIC OPTICAL-ELEMENTS" (Filing date: January 27, 2017) (Agent reference number MLEAP.103PR). This disclosure relates to optical systems, including display systems and augmented reality systems. Modern computing and display technologies are driving the development of systems for so-called "virtual reality" or "augmented reality" experiences, where digitally reproduced images or parts thereof are presented to the user in a manner that appears, or can be perceived, as real. Virtual reality or "VR" scenarios typically involve the presentation of digital or virtual imagery without transparency to other real-world visual inputs, while augmented reality or "AR" scenarios typically involve the presentation of digital or virtual imagery as an extension of the user's visualization of the real world around them. Mixed reality or "MR" scenarios are a type of AR scenario that typically involves virtual objects integrated into and responding to the natural world. For example, an MR scenario may include AR imagery that appears blocked by, or is perceived to interact with, objects in the real world in a different way. Referring to Figure 1, an augmented reality scene 10 is depicted. The user of the AR technology sees a real-world park-like setting 20 featuring people, trees, buildings in the background, and a concrete platform 30. The user also perceives "seeing" "virtual content" such as a robot figure 40 standing on the real-world platform 30 and a flying, cartoonish avatar character 50 that appears to be a personification of a bumblebee. These elements 50 and 40 are "virtual" in that they do not exist in the real world. The human visual perception system is complex, making it difficult to generate AR technology that facilitates a comfortable, natural, and rich presentation of virtual image elements among other virtual or real-world image elements. The systems and methods disclosed herein address various challenges related to AR or VR technologies. Figure 1 illustrates the user's view of augmented reality (AR) through an AR device. Figure 2 illustrates an embodiment of a wearable display system. Figure 3 illustrates a conventional display system for simulating three-dimensional images for the user. Figure 4 illustrates aspects of an approach to simulating a three-dimensional image using multiple depth planes. Figures 5A-5C illustrate the relationship between the radius of curvature and the focal radius. Figure 6 illustrates an example of a waveguide stack for outputting image information to the user. Figure 7 illustrates an example of an output beam produced by a waveguide. Figure 8 illustrates an embodiment of a stacked waveguide assembly, where each depth plane includes an image formed using multiple different primary colors. Figure 9A shows a cross-sectional side view of an embodiment of a stacked set of waveguides, each containing an internally coupled optical element. Figure 9B shows a perspective view of an embodiment of the multiple stacked waveguides shown in Figure 9A. Figure 9C shows top and bottom plan views of the embodiment of the multiple stacked waveguides shown in Figures 9A and 9B. Figure 10 shows a cross-sectional side view of an exemplary optical structure, including a metasurface and an anti-reflective coating. Figure 11A shows the upper and lower views of an exemplary metasurface equipped with an asymmetric Pancharatnam Berry phase optical element (PBOE). Figure 11B shows a perspective view of the metasurface of Figure 11A with an upper anti-reflective coating. Figure 11C is a plot of transmission and reflection as a function of the angle of incidence of light for an optical structure having the general structure shown in Figures 11A-11B. Figure 12A shows a cross-sectional perspective view of an exemplary metasurface, which includes an asymmetric diffraction grating and an anti-ref